MCSD MCSD Performance Optimization and Scalability 2

Question 1

In Azure App Service, which feature allows you to automatically increase or decrease the number of running instances based on CPU or memory metrics?

Accepted Answer

Autoscale

Answer

Azure App Service Autoscale monitors performance metrics and dynamically adjusts the instance count within defined minimum and maximum boundaries to handle varying load.

Question 2

What is the purpose of the ArrayPool<T> class in .NET when dealing with high-throughput scenarios?

Accepted Answer

To rent and return pre-allocated arrays, reducing garbage collection pressure

Answer

ArrayPool<T> maintains a pool of reusable arrays so hot code paths can rent a buffer, use it, and return it without triggering GC, significantly reducing memory allocation overhead.

Question 3

Which BenchmarkDotNet attribute is required to mark a method for micro-benchmarking in .NET?

Accepted Answer

[Benchmark]

Answer

[Benchmark] tells BenchmarkDotNet to run the decorated method repeatedly in a controlled harness, measuring its mean execution time, memory allocations, and other statistics.

Question 4

What does horizontal scaling (scale out) mean for an Azure-hosted web application compared to vertical scaling (scale up)?

Accepted Answer

Adding more VM instances to distribute load, rather than upgrading a single VM to a larger size

Answer

Horizontal scaling adds more identical instances behind a load balancer to spread traffic, offering better fault tolerance, whereas vertical scaling makes one machine more powerful.

Question 5

In Entity Framework Core, what does the Select() projection do to improve query performance compared to loading full entities?

Accepted Answer

It retrieves only the specified columns from the database instead of all columns

Answer

Projecting with Select() generates SQL that fetches only the columns you need, reducing the amount of data transferred from the database and the time spent materializing objects.

MCSD - Microsoft Certified Solutions Developer Practice Test

MCSD - Microsoft Certified Solutions Developer Practice Test

MCSD MCSD Performance Optimization and Scalability 2